24 research outputs found

    Catalogue of the spiders (Arachnida Araneae) of Sardinia

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    This catalogue summarizes and critically reviews araneological knowledge about Sardinian fauna. 140 publications from 1868 to 2012 were considered and about 4800 specimens belonging to 254 species were directly examined. The list report 495 species belonging to 229 genera divided into 43 families. For each species, literature, chorotype, regional distribution, and, where possible, habitats are indicated. Among the listed species Philodromus bosmansi Muster et Thaler, 2004 (Philodromidae) is new for Europe and the family of Prodidomidae with the species Zimirina brevipes P?rez et Blasco, 1986 is new for Italy. Also Setaphis parvula (Lucas, 1846) (Gnaphosidae), Centromerus succinus (Simon, 1884) and Hybocoptus corrugis (O. P.-Cambridge, 1875) (Linyphiidae) are new records for the Italian fauna and further 37 species are new for Sardinia. The genitalia of Phrurolithus corsicus (Simon, 1878), Zimirina brevipes, Drassodes luteomicans (Simon, 1878) and Zelotes dentatidens Simon, 1914 are illustrated

    Self-contained neuromusculoskeletal arm prostheses

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    We report the use of a bone-anchored, self-contained robotic arm with both sensory and motor components over 3 to 7 years in four patients after transhumeral amputation. The implant allowed for bidirectional communication between a prosthetic hand and electrodes implanted in the nerves and muscles of the upper arm and was anchored to the humerus through osseointegration, the process in which bone cells attach to an artificial surface without formation of fibrous tissue. Use of the device did not require formal training and depended on the intuitive intent of the user to activate movement and sensory feedback from the prosthesis. Daily use resulted in increasing sensory acuity and effectiveness in work and other activities of daily life

    Improved control of a prosthetic limb by surgically creating electro-neuromuscular constructs with implanted electrodes

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    : Remnant muscles in the residual limb after amputation are the most common source of control signals for prosthetic hands, because myoelectric signals can be generated by the user at will. However, for individuals with amputation higher up the arm, such as an above-elbow (transhumeral) amputation, insufficient muscles remain to generate myoelectric signals to enable control of the lost arm and hand joints, thus making intuitive control of wrist and finger prosthetic joints unattainable. We show that severed nerves can be divided along their fascicles and redistributed to concurrently innervate different types of muscle targets, particularly native denervated muscles and nonvascularized free muscle grafts. We engineered these neuromuscular constructs with implanted electrodes that were accessible via a permanent osseointegrated interface, allowing for bidirectional communication with the prosthesis while also providing direct skeletal attachment. We found that the transferred nerves effectively innervated their new targets as shown by a gradual increase in myoelectric signal strength. This allowed for individual flexion and extension of all five fingers of a prosthetic hand by a patient with a transhumeral amputation. Improved prosthetic function in tasks representative of daily life was also observed. This proof-of-concept study indicates that motor neural commands can be increased by creating electro-neuromuscular constructs using distributed nerve transfers to different muscle targets with implanted electrodes, enabling improved control of a limb prosthesis

    Application of a New Method for GWAS in a Related Case/Control Sample with Known Pedigree Structure: Identification of New Loci for Nephrolithiasis

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    In contrast to large GWA studies based on thousands of individuals and large meta-analyses combining GWAS results, we analyzed a small case/control sample for uric acid nephrolithiasis. Our cohort of closely related individuals is derived from a small, genetically isolated village in Sardinia, with well-characterized genealogical data linking the extant population up to the 16th century. It is expected that the number of risk alleles involved in complex disorders is smaller in isolated founder populations than in more diverse populations, and the power to detect association with complex traits may be increased when related, homogeneous affected individuals are selected, as they are more likely to be enriched with and share specific risk variants than are unrelated, affected individuals from the general population. When related individuals are included in an association study, correlations among relatives must be accurately taken into account to ensure validity of the results. A recently proposed association method uses an empirical genotypic covariance matrix estimated from genome-screen data to allow for additional population structure and cryptic relatedness that may not be captured by the genealogical data. We apply the method to our data, and we also investigate the properties of the method, as well as other association methods, in our highly inbred population, as previous applications were to outbred samples. The more promising regions identified in our initial study in the genetic isolate were then further investigated in an independent sample collected from the Italian population. Among the loci that showed association in this study, we observed evidence of a possible involvement of the region encompassing the gene LRRC16A, already associated to serum uric acid levels in a large meta-analysis of 14 GWAS, suggesting that this locus might lead a pathway for uric acid metabolism that may be involved in gout as well as in nephrolithiasis

    Neural feedback strategies to improve grasping coordination in neuromusculoskeletal prostheses

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    Conventional prosthetic arms suffer from poor controllability and lack of sensory feedback. Owing to the absence of tactile sensory information, prosthetic users must rely on incidental visual and auditory cues. In this study, we investigated the effect of providing tactile perception on motor coordination during routine grasping and grasping under uncertainty. Three transhumeral amputees were implanted with an osseointegrated percutaneous implant system for direct skeletal attachment and bidirectional communication with implanted neuromuscular electrodes. This neuromusculoskeletal prosthesis is a novel concept of artificial limb replacement that allows to extract control signals from electrodes implanted on viable muscle tissue, and to stimulate severed afferent nerve fibers to provide somatosensory feedback. Subjects received tactile feedback using three biologically inspired stimulation paradigms while performing a pick and lift test. The grasped object was instrumented to record grasping and lifting forces and its weight was either constant or unexpectedly changed in between trials. The results were also compared to the no-feedback control condition. Our findings confirm, in line with the neuroscientific literature, that somatosensory feedback is necessary for motor coordination during grasping. Our results also indicate that feedback is more relevant under uncertainty, and its effectiveness can be influenced by the selected neuromodulation paradigm and arguably also the prior experience of the prosthesis user

    A highly integrated bionic hand with neural control and feedback for use in daily life

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    Restoration of sensorimotor function after amputation has remained challenging because of the lack of human-machine interfaces that provide reliable control, feedback, and attachment. Here, we present the clinical implementation of a transradial neuromusculoskeletal prosthesis-a bionic hand connected directly to the user's nervous and skeletal systems. In one person with unilateral below-elbow amputation, titanium implants were placed intramedullary in the radius and ulna bones, and electromuscular constructs were created surgically by transferring the severed nerves to free muscle grafts. The native muscles, free muscle grafts, and ulnar nerve were implanted with electrodes. Percutaneous extensions from the titanium implants provided direct skeletal attachment and bidirectional communication between the implanted electrodes and a prosthetic hand. Operation of the bionic hand in daily life resulted in improved prosthetic function, reduced postamputation, and increased quality of life. Sensations elicited via direct neural stimulation were consistently perceived on the phantom hand throughout the study. To date, the patient continues using the prosthesis in daily life. The functionality of conventional artificial limbs is hindered by discomfort and limited and unreliable control. Neuromusculoskeletal interfaces can overcome these hurdles and provide the means for the everyday use of a prosthesis with reliable neural control fixated into the skeleton

    Application of a new method for GWAS in a related case/control sample with known pedigree structure: identification of new loci for nephrolithiasis

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    In contrast to large GWA studies based on thousands of individuals and large meta-analyses combining GWAS results, we analyzed a small case/control sample for uric acid nephrolithiasis. Our cohort of closely related individuals is derived from a small, genetically isolated village in Sardinia, with well-characterized genealogical data linking the extant population up to the 16(th) century. It is expected that the number of risk alleles involved in complex disorders is smaller in isolated founder populations than in more diverse populations, and the power to detect association with complex traits may be increased when related, homogeneous affected individuals are selected, as they are more likely to be enriched with and share specific risk variants than are unrelated, affected individuals from the general population. When related individuals are included in an association study, correlations among relatives must be accurately taken into account to ensure validity of the results. A recently proposed association method uses an empirical genotypic covariance matrix estimated from genome-screen data to allow for additional population structure and cryptic relatedness that may not be captured by the genealogical data. We apply the method to our data, and we also investigate the properties of the method, as well as other association methods, in our highly inbred population, as previous applications were to outbred samples. The more promising regions identified in our initial study in the genetic isolate were then further investigated in an independent sample collected from the Italian population. Among the loci that showed association in this study, we observed evidence of a possible involvement of the region encompassing the gene LRRC16A, already associated to serum uric acid levels in a large meta-analysis of 14 GWAS, suggesting that this locus might lead a pathway for uric acid metabolism that may be involved in gout as well as in nephrolithiasis

    Nerve transfers of the forearm and hand: a review of current indications

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    Nerve transfer surgery, also referred to neurotization, developed in the mid 1800s with the use of animal models, and was later applied in the treatment of brachial plexus injuries. Neurotization is based on the concept that following a proximal nerve lesion with a poor prognosis, expendable motor or sensory nerves can be re-directed in proximity of a specific target, whether a muscle or skin territory, in order to obtain faster re-innervation. Thanks to the contribution of several authors including Oberlin, MacKinnon and many others, the field of nerve transfer surgery has expanded in treatment of not only the brachial plexus, but also the arm, forearm and hand. This article reviews the recent literature regarding current concepts in nerve transfer surgery, including similarities to and differences from tendon transfer surgery. Moreover, indications and surgical techniques are illustrated for different types of nerve injury affecting the extrinsic and intrinsic musculature of the hand as well as sensory function

    Probabilistic Models and Fragility Estimates for Unreinforced Masonry Walls Subject to In-Plane Horizontal Forces

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    Unreinforced masonry (URM) buildings make up a significant portion of the built environment, with hollow clay being the predominant choice for the units. The capacity of URM buildings is a function of the capacity of its walls, both to vertical and horizontal forces. However, URM is particularly vulnerable to the effect of horizontal forces due to the low tensile strength of the mortar that holds the units together. URM walls are subject to significant in-plane horizontal forces during seismic events, so that a proper quantification of the capacity of URM walls to this type of forces is required. The models in design codes are often conservative and do not capture the uncertainties required for estimating the failure probability of URM walls. This paper develops probabilistic capacity models for URM walls with hollow clay units subject to horizontal in-plane forces. The models are developed considering diagonal cracking, flexural/rocking, and sliding failure as possible failure modes. The models are constructed starting from existing physics-based models that attempt to capture the underlying physics, and then developing correction terms that improve the accuracy of the models and remove the inherent bias. Unknown parameters for the proposed models are calibrated using a Bayesian updating approach. The proposed models are probabilistic and capture the relevant uncertainties. The proposed models are used to assess fragility functions of example URM walls subject to horizontal in-plane forces. The comparison of the fragility functions shows the effect of selected variables
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